Precipitant for recovering metals from solutions.



in precipitants for recovering metals from" No Drawing.

GALEN HOWELL OLEVENGER, OF PALO ALTO, CALIFORNIA, ASSIGNOR TO "MERRILL METALLURGICAL COMPANY, A CORPORATION OF CALIFORNIA.

PRECIPITANT FOB. RECOVERING METALS FROM SOLUTIONS.

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America, and resident of Palo Alto, Santa Clara countyfistate of California, have invented new and useful Improvements in Precipitants for Recovering Metals from Solutions, of which thefollowing is a specification.

My invention relates to an improvement solutions, and particularly to that class of precipitant which is employed for the purpose of precipitating precious metals from cyanid solutions. p In practice, various forms of precipitants are used, but the most satisfactory and economical preci'pitants which have hitherto been employed in this art, are precipitant-s composed of malleable metallic zinc in' the form of either threads or spheres, the

spheres composing what is known in prac-.

tice as zinc fume or zinc dust.

' account of its malleability, metallic zinc has hitherto resisted any form of mechanical comminution down to a powder which will expose sufiicient surface to enable it to be used in a process of precipitation which involves agitation, conduction of the mixture, and the subsequent filtration thereof.

Now, I have discovered that where a precipitant is employed composed of a suitable alloy of zinc, which may be easily comminuted to an angular powder, and which is introduced into the solution to be treated in such form, an economical, easily regulated, and metallurgically efficient precipitation results, which is free from the defects which have hitherto existed in precipitation For this purpose I use preferably sodium as I find that it is the cheapest substance practicable and less likely to give trouble through the formatip of insoluble compounds than other-metals,

and at the same time givesthe desired degree. of brittleness. The alloy produced will have very 'inuch greater efficiency from a chemical point of view,'as the presence of Specification of Letters Patent. Patented J 31L 5 11915 Application filed June 11, 1912. Serial No. 702,973.

the sodium, and possibly thelead in the alloy, bring about a. quicker action and necessitate the use of a smaller amount of precipitant, even though the: mechanical subdivision remains approximately the same.

In practice, such a brittle alloy is conrposed. of zinc, mixed preferably with not overthree per cent. of sodium, or any other alkali or alkaline earth metal' which Will impart brittleness to the resultant alloy, or

any one or more of these metals in suitable proportions, dependent upon the character .Of the solution to be precipitated and the point of saturation of any particular metal in the alloy employed, and is prepared in any convenient form of reducing receptacle in-which they can be; brought together. In practice, a vessel is used in which the alloy can be compounded with a minimum of oxidation. After the alloy is formed, and allowed to cool, it may be readily and quickly reduced to an angular powder in any convenient form of comminuting apparatus.

The powder thus formed may lie used as a. precipitant in the place of. the various forms of metallic zinc precipitants which have hitherto been used in any of the wellknown processes of cyanidation, according to the practice of those processes.

I claim as my invention:

1. A precipitant for recovering metals f .0111 cyanid solutions, consisting of a binary rittle alloy of zinc with alkali or alkaline earth metal. 1'

2. A precipitant for recovering metals from cyanid solutions, consisting of a powder made from a brittle alloy, consisting of Zinc and alkali or alkaline earth metal, susceptibleof reduction to any degree of fine ness.

3. A precipitant for the recoveryof metals from cya'ld solutions, conslstmg of brittle alloy of zinc and not more than three per cent. (3%) of alkali or alkaline earth metal.

'4. A precipitant for the recovery of metals from cyanid solutions, conisting of April, 1912.

G. HOWELL CLEVENGER.

"Witnesses C. C. BROADWATER, HERBERT S. SHUEY.

presence of two Witnesses, this 18th day of v 

